This invention relates to a system for applying a sleeve-type wrapper to an elongated article such as a compressible elongated stack or log of interfolded paper towels or the like.
Articles such as paper towels are typically packaged by compressing a stack of articles and applying a pair of webs about the compressed stack. The webs are applied such that end portions of the webs overlap each other, and an adhesive is placed between the overlapping portions of the webs. The webs are thus secured together about the stack, to form a band or wrapper that maintains the stack in compression during shipment and storage.
Different types of wrapping or banding systems have been developed for wrapping a compressed stack of articles such as paper towels. In one such system, a stack of interfolded paper towels is first cut to length, and is advanced by a pair of convergent belts which apply compression to the stack. Top and bottom sheets of wrapping material are applied about the compressed stack, such that the side edges of the sheets overlap each other, and the overlapping side edges are secured together by an adhesive so as to form individually wrapped packages. In another system, the individual sheets of wrapping material are replaced with upper and lower rolled webs of wrapping material, which are applied to an elongated log or stack of interfolded paper towels. The stack is simultaneously advanced and compressed, and the upper and lower webs are unwound from the supply rolls of web material and applied to the compressed stack such that the side edges of the upper and lower webs of wrapping material overlap each other. Adhesive is applied between the overlapping side edges of the webs, which are pressed together as the stack is advanced through a discharge section of the apparatus, which allows the adhesive to set. The webs are severed in a location corresponding to the end of the stack or log, such that the upper and lower webs are applied to the full length of the log. The wrapped log is then supplied to a cutting mechanism such as a log saw, where the log is cut into lengths according to customer specifications in preparation for packaging and shipment. This type of system is advantageous in that a relatively long stack or log can be wrapped in a single wrapping operation, and subsequently cut into individual packages of any desired length.
Advances in interfolding technology have enabled production of a substantially continuous stack or log of articles such as interfolded paper towels. However, drawbacks are associated with utilization of packaging or banding systems as described above in connection with a continuously produced log of paper towels. In order to adapt the prior art wrapping system, the continuous log must be cut to length to form individual stacks which are then wrapped or banded. This detracts from the overall goal of a continuous production facility by adding the step of cutting the continuously produced log prior to wrapping. While other types of prior art wrapping systems provide the ability to wrap a relatively long article by supplying the wrapping material from rolls, the maximum length of the log that can be wrapped is dictated by the length of the web of wrapping material wound onto the supply roll.
It is an object of the present invention to provide a system for applying a sleeve-type package or wrapper to an elongated article, which is capable of providing continuous operation so as to enable packaging of a continuous article, such as an elongated continuous stack or log of interfolded paper towels. Another object of the invention is to provide such a system in which the webs of wrapping material are applied in a manner similar to that of the prior art, to produce packages, such as wrapped paper towels, that have essentially the same construction as in the prior art. Another object of the invention is to provide such a system which has the capability to continuously wrap an elongated article and which requires minimal manpower to maintain the supply of wrapping material. Yet another object of the invention is to provide such a system which utilizes existing technological concepts in advancement of the elongated article, such as the continuous stack or log of interfolded paper towels, and incorporates a feature for continuously supplying wrap material.
In accordance with the present invention, a system for wrapping an elongated article, such as a continuous stack or log of interfolded paper towels, includes an advancing mechanism engaged with the elongated article, which is operable to advance the elongated article in a direction along a longitudinal axis defined by the elongated article. The system further includes a first web supply arrangement for continuously supplying a first web of wrapping material, and a second web supply arrangement for continuously supplying a second web of wrapping material. The system further includes a web application arrangement for applying the first and second webs of wrapping material to the elongated article as the elongated article is advanced by the advancing mechanism. The web application arrangement is operable to apply the first and second webs such that adjacent end areas of the first and second webs overlap each other. The system further includes a bonding arrangement for bonding the overlapping end areas of the first and second webs together so as to secure the first and second webs about the elongated article.
The first and second web supply arrangements each include a pair of web supply stations, each of which is adapted to supply a web of wrapping material from a source such as a supply roll. Each of the first and second web supply arrangements further includes a splicing mechanism, which is operable to splice together the trailing end of a web of wrapping material from one of the sources with the leading end of the web of wrapping material from the other of the sources, to provide a continuous supply of the web of wrapping material to the web application arrangement. The trailing and leading ends of the respective webs of wrapping material are temporarily maintained stationary while the splicing mechanism splices the web ends together. Each web supply arrangement further includes a take-up or traveling web storage arrangement downstream of the splicing mechanism and upstream of the web application arrangement. In this manner, the web of wrapping material is continuously supplied to the web application arrangement from the take-up or storage arrangement while the ends of the respective webs are maintained stationary for splicing together. In one form, the take-up or storage arrangement is in the form of a festoon-type mechanism consisting of a series of stationary rollers and a series of movable rollers which are movable toward and away from the stationary rollers, and the web of wrapping material is trained about both the stationary and movable rollers. While the web ends are maintained stationary for splicing, the web of wrapping material continues to be advanced downstream of the splicing arrangement, and the movable rollers of the festoon-type mechanism are moved toward the stationary rollers to enable a continuous supply of the web of wrapping material to the web application arrangement during the splicing operation. Subsequently, the spliced web is allowed to be advanced, to enable the movable rollers to again be moved away from the stationary rollers so as to restore the length of the web that travels through the festoon-type mechanism to any amount sufficient to accommodate a subsequent splicing operation. In one embodiment, the movable rollers are carried by a movable arm, which provides the storage capacity for the web of wrapping material so as to enable the web of wrapping material to continuously be supplied to the web application arrangement while the web ends are maintained stationary during the splicing operation.
The advancing mechanism is operable to advance the elongated article in a first direction along the longitudinal axis define by the elongated article. The first and second web supply arrangements are oriented so as to supply the first and second webs of wrapping material in a second direction transverse to the first direction, such that the web supply arrangements do not interfere with the elongated article as it is supplied to the advancing mechanism. Each of the first and second webs of wrapping material is engaged with a diverter located between the respective web supply arrangement and the web application arrangement, to change the direction of movement of the web from the second direction to the first direction prior to supply of the web to the web application arrangement.
Each web supply station is configured to supply a web of wrapping material from a source, such as a supply roll of wrapping material which is rotatably supported at the web supply station, e.g. by engagement with a spindle or the like. An unwind mechanism is provided at each web supply station for imparting rotation to the web supply roll. In one embodiment, the unwind mechanism is a pivoting belt-type arrangement that engages the outer surface of the roll to assist in rotating the roll about the spindle. Each web supply station further includes a hoist for use in lifting the supply roll and engaging the supply roll with the spindle.
The invention contemplates an apparatus for wrapping an elongated article such as a continuous stack or log of interfolded paper towels, as well as a method of wrapping an elongated article, substantially in accordance with the foregoing summary.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.